US2776376A - Multiple band tuning device - Google Patents

Multiple band tuning device Download PDF

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Publication number
US2776376A
US2776376A US327242A US32724252A US2776376A US 2776376 A US2776376 A US 2776376A US 327242 A US327242 A US 327242A US 32724252 A US32724252 A US 32724252A US 2776376 A US2776376 A US 2776376A
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Prior art keywords
capacitance
stator
section
tuning
plates
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US327242A
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Matthew W Slate
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Allen B du Mont Laboratories Inc
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Allen B du Mont Laboratories Inc
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G5/00—Capacitors in which the capacitance is varied by mechanical means, e.g. by turning a shaft; Processes of their manufacture
    • H01G5/38—Multiple capacitors, e.g. ganged
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J3/00—Continuous tuning
    • H03J3/20—Continuous tuning of single resonant circuit by varying inductance only or capacitance only

Definitions

  • the present-invention solves the problenrbyproviding a single condenser unit having two or more stator-'sec-- tions arranged to cooperate with a single rotor section, the statorsections being selectively used in cooperation with. different tuning coils.
  • An object of the invention is to. provide a multiband tuner which is eflicient andv physicallycompact, and.
  • Another object is to provide a tuning condenser having two or more stator sections which selectivelyfunction in combination with a single rotor section, and to provide such a tuning condenser in-which both statorsections tune with the same or a predetermined characteristic or; ratio of capacitance variation.
  • Figurel is a front elevational view of a-preferred embodiment of the novel tuning condenser in accordance with the present invention.
  • Figure 2 is a side elevational view of the device of Figurel looking towards the right hand side thereof;
  • FIG. 3 is an electrical diagram showingthe novel tuning condenser connected to selectively cooperate with differing tuning coils or inductances;
  • Figure 4 is a side view of an alternative embodiment of the invention.
  • the novel tuning condenser in its preferred embodiment, is of the type known in the art as a split-stator condenser, and comprises an insulative base 11 having attached thereto a large-capacitance stator section 12 and a low-capacitance stator section 13.
  • the large-capacitance stator section 12 comprises one or more flat conductive plates 16, 17 arranged in parallel alignment and nited States Patent connected to an electrical terminal 18.
  • the smallcapacitance stator section 13 comprises one or more fiatconductive plates: 21, 22 arranged in. parallel alignment with respect to. each other and with respect to the largecapacitance'stator section 12-; i. e.,.the plates 21, 22 are.
  • the preferred embodiment shows the preferred embodiment as having; the same number of plates in; the low-capacitance stator section as in the large-capacitance stator section, this is not mandatory, i. e., the number of plates in the low capacitance stator section may be more or less than the number of plates in the large-capacitance stator section.
  • Allof the platesZ-l, 22 of the low capacitance stator section 13 are connected to a-common'electrical terminal 26;
  • the large-capacitance plates may be physically asecond set of large-capacitancestator plates comprisingelectrically'conductive plates 16' and li and also comprising a section-oflow-capacitance stator plates 21' and 22, are-positionedonthe basel-ltin axial alignment with the firstmentioned stator sections 12-and 13.
  • A- rotatableshaftsl'of electrically conductive material is positioned in a parallel relationship with respect to the-base 11.
  • a rotor-section 32 comprising electricallyconductive-roton plates 33, 34 and 35, is positioned on the shaft 3l so that therotor plates will-enmesh with but not-touch the-stator. plates 16, 17 and 21; 22-sirnultaneously or in a predeterminedvmanner when the shaft 31: is rrotated.
  • a second rotor section 32, comprising electrically conductive plates 33, 34 and-35 is positioned on the shaft 31 in a like relationship with respect to thesecond set of stator plates :12- and 13. The rotor sections32 and 32 rotate in'-unison when the shaft 3f is. rotated.-
  • stator plates andof the rotor'plates are preferably as shownin the drawing, or equivalent, in order to achieveadesired tracking or characteristic of capacitance variation, as will be described.
  • Ashoulder'od is shown provided in the plates of the large-capacitance stator section-l2, so that the lower corner 37' of-the' rotor 32 will be unmeshed from the large-capacitance section l2-when the rotor 32is rotatedto its .raised or minimum capacitance position.
  • the minimum capacitance obtainable between the rotor 32 and the stator sections 12 and 13 will occur at the same angularpositionof the shaft 31.
  • thelow-capacitance section 13 is positioned relatively near to or under the shaft'Sl, whereas thelarge-capacitance sectionlZ is positioned relatively far from the-shaft 31.
  • This arrangement provides improved results, since the rotor section 32 has a relatively greater linearmovement ata' greater disance from the shaft 31 where the large-capacitance stator section 12 is positioned, and-has relatively less.linear movement at a shorter distance from the shaft 31 where the smallcapacitance stator section 13 is positioned.
  • a sliding switch mechanism 41 comprising an insulative member 42 having attached thereto sets of electrical contacts.
  • Fixed contacts 4651 are provided to selectively engage contacts on the slider mechanism 41 when the latter is moved.
  • the fixed contacts 46 and 51 are shown connected to electrical circuits 52, 53, which may be oscillators, amplifiers, mixers,
  • a pair of fixed contacts 47, 50 are connected to the large-capacitance stator sections 12 and 12', and another pair of fixed contacts 48, 49 are connected to the small-capacitance stator sections 13 and 13'.
  • Each set of contacts on the sliding mechanism 41 comprises a plurality of contacts 56-61 arranged to simultaneously engage the respective fixed contacts 46-51.
  • a low frequency coil 66 is shown connected at one end to contacts 56 and 57, and at the other end to contacts 68 and 61.
  • This arrangement connects the coil 66 in shunt with the large-capacitance stator sections 12 and 12 and also to the electrical circuits 52, 53, when the mechanism 41 is in one of its selective positions.
  • Another tuning section comprises a high frequency coil 67 connected at the ends thereof to the contacts 56a, 58a, and 59a, 61a.
  • Another tuned section comprises a pair of low-frequency coils 68, 69 respectively connected between the contacts 56!), 57b and 60b, 6112.
  • these coils 68, 69 may be selectively connected in series wtih the circuits 52, 53 and the large-capacitance stator sections 12, 12.
  • a pair of high-frequency coils 71, 72 may be respectively connected between contacts 566, 58c and 59c, 61c, in order to selectively connect these coils in series with the small-capacitance stator sections 13, 13.
  • the contacts can be connected so that the low-capacitance stator sections 13, 13 will be connected in electrical parallel with the large-capacitance stator sections 12, 12.
  • a coil 76 may be thus shunt-connected by having an end thereof connected to the contacts 56d, 57d and 58d, the other end being connected to the contacts 59d, 60a, and 610'.
  • a pair of coils '77, 78 may be selectively series-connected through both stator sections, if one coil 77 is connected between contacts 56c and 57e, 58c and the coil 78 is connected between the contacts 61:: and 59c, 602.
  • the novel tuning circuit accomplishes efficient electrical operation over a wide range of tuning frequencies in cooperation with different inductance coils having widely differing values of inductance.
  • the novel system achieves increased tuning range over each of the difiering coil ranges by virtue of providing a tuning condenser having a low minimum capacitance value in cooperation with the small inductance coils and by providing a larger capacitance condenser in coperation with the larger inductance coils. If a larger capacitance condenser were attempted to be used in cooperation with a small inductance coil, even the minimum capacity of such a condenser would be too great for proper operation of 4 the coil, and the electrical efficiency and Q would be low.
  • stator sections 12 and 13 may be so shaped and arranged and the rotor section 32 may be so shaped and arranged that the tracking or characteristic of capacitance or frequency variation, will be the same for different values of inductance coils used in the circuit.
  • a multiple-band tuning device comprising a tuning condenser having a rotor section rotatable about an axis and a plurality of stator sections positioned substantially in a common plane near the path of said rotor section, said stator sections being positioned at respectively different distances from said axis whereby the capacitances between said rotor section and the respective stator sections will vary simultaneously, one of said stator sections being shaped and positioned to provide a larger capacitance than another of said stator sections, a plurality of inductance members having differing inductance values, and means for selectively switching the largervalue ones of said inductance members to said largercapacitance stator section and the smaller-values ones of said inductances to said lower-capacitance stator sections.
  • said switching means comprises a movable switch plate having a row of contactors to which said larger-value inductances are respectively connected, another row of contactors parallel to said first row to which said lowervalue inductances are respectively connected, a fixed contactor electrically connected to said larger-capacitance stator section and positioned to selectively engage said row of movable contactors to which said larger-value inductances are connected, and another fixed contactor electrically connected to said smaller-capacitance stator section and positioned to selectively engage said row of movable contactors to which said lower-value inductances are connected.

Description

Jan. 1, 1957 M. w. SLATE MULTIPLE BAND-TUNING DEVICE 2 Sheets-Sheet 1 Filed Dec. 22, 1952 E .T mm m m m VW 0 mw n M m M v s 2 m 2 2 /i la] 2 .mw F
Jan. 1, 1957 M. w. SLATE MULTIPLE BAND TUNING DEVICE.
2 Sheets-Sheet 2 Filed Dec. 22, .1952
INVENTOR. 7 MATTHEW W. SLATE Fig. 4
A TTORNEYS MULTIPLE EAND' TUBING; DEVICE Matthew W. Slate, New York, N. Y., assiguor to Allen B. Du Mont Laboratories, lino, Qlifton, N. .l., a corporation of Delaware Application December 22, 1952, Serial No. 327,242.
2 (Elaims. (Cl. 250-40) of frequencies are to be tuned. Such anarrangement isnot suitable, since low frequencies require arelatively large value of tuning condenser capacitance and variation thereof in order to tune over a desired range of frequencies, whereas higher frequencies. require a relatively;
small value of capacitance and'variation thereof, which must also becapable of adjustment to a small value of Thus, a singletuning condenser is unsuitable where widely differing ranges of frequencies:
minimum capacitance.
are to be tuned; In the prior art, the problem has frequently been solved by providing anindividual-tuning condenser for use with each coil. This, of course,- entails extra expense and sometimes unwieldy andqbulky arrangements of components.
The present-invention solves the problenrbyproviding a single condenser unit having two or more stator-'sec-- tions arranged to cooperate with a single rotor section, the statorsections being selectively used in cooperation with. different tuning coils.
An object of the invention is to. provide a multiband tuner which is eflicient andv physicallycompact, and.
which is suitable for tuning the V. H. F. and..U. H. F. television frequencies.
Another object is to provide a tuning condenser having two or more stator sections which selectivelyfunction in combination with a single rotor section, and to provide such a tuning condenser in-which both statorsections tune with the same or a predetermined characteristic or; ratio of capacitance variation.
Other objects and features of the invention will be apparent when the following description is considered together with the annexed drawings, in-which,
Figurel is a front elevational view of a-preferred embodiment of the novel tuning condenser in accordance with the present invention;
Figure 2 is a side elevational view of the device of Figurel looking towards the right hand side thereof;
Figure 3 is an electrical diagram showingthe novel tuning condenser connected to selectively cooperate with differing tuning coils or inductances; and
Figure 4 is a side view of an alternative embodiment of the invention.
The novel tuning condenser, in its preferred embodiment, is of the type known in the art as a split-stator condenser, and comprises an insulative base 11 having attached thereto a large-capacitance stator section 12 and a low-capacitance stator section 13. The large-capacitance stator section 12 comprises one or more flat conductive plates 16, 17 arranged in parallel alignment and nited States Patent connected to an electrical terminal 18. The smallcapacitance stator section 13 comprises one or more fiatconductive plates: 21, 22 arranged in. parallel alignment with respect to. each other and with respect to the largecapacitance'stator section 12-; i. e.,.the plates 21, 22 are.
positioned in the same planes. as the respective largecapacitance stator plates 16, 17. Although the drawing:
shows the preferred embodiment as having; the same number of plates in; the low-capacitance stator section as in the large-capacitance stator section, this is not mandatory, i. e., the number of plates in the low capacitance stator section may be more or less than the number of plates in the large-capacitance stator section.
Allof the platesZ-l, 22 of the low capacitance stator section 13 are connected toa-common'electrical terminal 26; The large-capacitance plates may be physically asecond set of large-capacitancestator plates comprisingelectrically'conductive plates 16' and li and also comprising a section-oflow-capacitance stator plates 21' and 22, are-positionedonthe basel-ltin axial alignment with the firstmentioned stator sections 12-and 13.
A- rotatableshaftsl'of electrically conductive material is positioned in a parallel relationship with respect to the-base 11. A rotor-section 32, comprising electricallyconductive- roton plates 33, 34 and 35, is positioned on the shaft 3l so that therotor plates will-enmesh with but not-touch the-stator. plates 16, 17 and 21; 22-sirnultaneously or in a predeterminedvmanner when the shaft 31: is rrotated. A second rotor section 32, comprising electrically conductive plates 33, 34 and-35 is positioned on the shaft 31 in a like relationship with respect to thesecond set of stator plates :12- and 13. The rotor sections32 and 32 rotate in'-unison when the shaft 3f is. rotated.-
The particular shapes of the stator plates andof the rotor'plates arepreferably as shownin the drawing, or equivalent, in order to achieveadesired tracking or characteristic of capacitance variation, as will be described. Ashoulder'odis shown provided in the plates of the large-capacitance stator section-l2, so that the lower corner 37' of-the' rotor 32 will be unmeshed from the large-capacitance section l2-when the rotor 32is rotatedto its .raised or minimum capacitance position. Thus, the minimum capacitance obtainable between the rotor 32 and the stator sections 12 and 13 will occur at the same angularpositionof the shaft 31.
As shown, thelow-capacitance section 13 is positioned relatively near to or under the shaft'Sl, whereas thelarge-capacitance sectionlZ is positioned relatively far from the-shaft 31. This arrangement provides improved results, since the rotor section 32 has a relatively greater linearmovement ata' greater disance from the shaft 31 where the large-capacitance stator section 12 is positioned, and-has relatively less.linear movement at a shorter distance from the shaft 31 where the smallcapacitance stator section 13 is positioned.
Now referring to the electrical circuit of Figure 3, there is shown, in addition to the novel split-stator embodiment of the invention, a sliding switch mechanism 41 comprising an insulative member 42 having attached thereto sets of electrical contacts. Fixed contacts 4651 are provided to selectively engage contacts on the slider mechanism 41 when the latter is moved. The fixed contacts 46 and 51 are shown connected to electrical circuits 52, 53, which may be oscillators, amplifiers, mixers,
Fatented- Jan. it);
or the like. A pair of fixed contacts 47, 50 are connected to the large-capacitance stator sections 12 and 12', and another pair of fixed contacts 48, 49 are connected to the small-capacitance stator sections 13 and 13'.
Each set of contacts on the sliding mechanism 41 comprises a plurality of contacts 56-61 arranged to simultaneously engage the respective fixed contacts 46-51. By way of example, several sets of coils or inductances are represented on the sliding mechanism 41. A low frequency coil 66 is shown connected at one end to contacts 56 and 57, and at the other end to contacts 68 and 61. This arrangement connects the coil 66 in shunt with the large- capacitance stator sections 12 and 12 and also to the electrical circuits 52, 53, when the mechanism 41 is in one of its selective positions. Another tuning section comprises a high frequency coil 67 connected at the ends thereof to the contacts 56a, 58a, and 59a, 61a. Thus, when the mechanism 41 is properly moved, the coil 67 will become connected in shunt to the smallcapacitance stator sections 13, 13 and to the electrical circuits 52, 53.
Another tuned section comprises a pair of low-frequency coils 68, 69 respectively connected between the contacts 56!), 57b and 60b, 6112. Thus, these coils 68, 69 may be selectively connected in series wtih the circuits 52, 53 and the large- capacitance stator sections 12, 12. Similarly, a pair of high- frequency coils 71, 72 may be respectively connected between contacts 566, 58c and 59c, 61c, in order to selectively connect these coils in series with the small- capacitance stator sections 13, 13.
To achieve an increased capacitance effect, the contacts can be connected so that the low- capacitance stator sections 13, 13 will be connected in electrical parallel with the large- capacitance stator sections 12, 12. As shown, a coil 76 may be thus shunt-connected by having an end thereof connected to the contacts 56d, 57d and 58d, the other end being connected to the contacts 59d, 60a, and 610'. Also, a pair of coils '77, 78 may be selectively series-connected through both stator sections, if one coil 77 is connected between contacts 56c and 57e, 58c and the coil 78 is connected between the contacts 61:: and 59c, 602.
It will be understood that when tuning ranges are changed, by switching or sliding the support 42 so as to engage different coils in the tuned circuit, the proper stator elements automatically become connected into the circuit, i. e., the large capacitance stator sections are automatically employed in cooperation with the large inductance coils whereas the small capacitance stator sections are automatically connected in cooperation with the low-inductance coils.
From the foregoing, it will be appreciated that the novel tuning circuit accomplishes efficient electrical operation over a wide range of tuning frequencies in cooperation with different inductance coils having widely differing values of inductance. The novel system achieves increased tuning range over each of the difiering coil ranges by virtue of providing a tuning condenser having a low minimum capacitance value in cooperation with the small inductance coils and by providing a larger capacitance condenser in coperation with the larger inductance coils. If a larger capacitance condenser were attempted to be used in cooperation with a small inductance coil, even the minimum capacity of such a condenser would be too great for proper operation of 4 the coil, and the electrical efficiency and Q would be low.
In addition to the advantages above described which are afforded by the invention, the stator sections 12 and 13 may be so shaped and arranged and the rotor section 32 may be so shaped and arranged that the tracking or characteristic of capacitance or frequency variation, will be the same for different values of inductance coils used in the circuit. This permits a tuning dial, for instance, to be calibrated in several scales which are essentially linear.
While a preferred embodiment of the invention has been shown in the form of a split-stator tuning condenser, it will be appreciated by those skilled in the art that single section condensers may be likewise employed, and that other modifications of the invention may be made without departing from the spirit and scope thereof. The scope of the invention is defined in the following claims.
What is claimed is:
1. A multiple-band tuning device comprising a tuning condenser having a rotor section rotatable about an axis and a plurality of stator sections positioned substantially in a common plane near the path of said rotor section, said stator sections being positioned at respectively different distances from said axis whereby the capacitances between said rotor section and the respective stator sections will vary simultaneously, one of said stator sections being shaped and positioned to provide a larger capacitance than another of said stator sections, a plurality of inductance members having differing inductance values, and means for selectively switching the largervalue ones of said inductance members to said largercapacitance stator section and the smaller-values ones of said inductances to said lower-capacitance stator sections.
2. The device in accordance with claim 1, in which said switching means comprises a movable switch plate having a row of contactors to which said larger-value inductances are respectively connected, another row of contactors parallel to said first row to which said lowervalue inductances are respectively connected, a fixed contactor electrically connected to said larger-capacitance stator section and positioned to selectively engage said row of movable contactors to which said larger-value inductances are connected, and another fixed contactor electrically connected to said smaller-capacitance stator section and positioned to selectively engage said row of movable contactors to which said lower-value inductances are connected.
References Cited in the file of this patent UNITED STATES PATENTS 1,672,367 Cardwell June 5, 1928 1,904,165 Mullner Apr. 18, 1933 2,169,257 Krebs et a1. Aug. 15, 1939 2,223,061 Ducati NOV. 26, 1940 2,295,173 Hoffman et al. Sept. 8, 1942 2,344,689 Frazier Mar. 21, 1944 2,443,935 Shea June 22, 1948 2,557,969 Isley June 26, 1951 FOREIGN PATENTS 464,254 Great Britain Apr. 14, 1937 591,258 Great Britain Aug. 12, 1947
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2886700A (en) * 1953-02-04 1959-05-12 Standard Coil Prod Co Inc Uhf-vhf tuners
US2913644A (en) * 1956-07-09 1959-11-17 Rca Corp Variable capacitor
US3056075A (en) * 1957-11-07 1962-09-25 Brayhead Ascot Ltd Turret tuners

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1672367A (en) * 1925-11-12 1928-06-05 Allen D Cardwell Variable air condenser
US1904165A (en) * 1929-02-18 1933-04-18 Telefunken Gmbh Variable condenser
GB464254A (en) * 1936-09-24 1937-04-14 Haardt & Co Ag Improvements in variable electrical condensers
US2169257A (en) * 1930-05-24 1939-08-15 William N Krebs Multifrequency signaling apparatus
US2223061A (en) * 1936-12-19 1940-11-26 Ducati Adriano Cavalieri Arrangement of noninductive terminals for variable condensers
US2295173A (en) * 1940-06-20 1942-09-08 Sonora Radio & Television Corp Step-wise tuning of electrical circuits
US2344689A (en) * 1942-03-12 1944-03-21 Bendix Aviat Corp Variable capacitor
GB591258A (en) * 1944-05-12 1947-08-12 Patelhold Patentverwertung Improvements in or relating to short-wave tuning systems
US2443935A (en) * 1942-01-07 1948-06-22 Gen Electric Superheterodyne radio receiver
US2557969A (en) * 1948-12-29 1951-06-26 Frank C Isely Shielded ultra high frequency tuning apparatus

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1672367A (en) * 1925-11-12 1928-06-05 Allen D Cardwell Variable air condenser
US1904165A (en) * 1929-02-18 1933-04-18 Telefunken Gmbh Variable condenser
US2169257A (en) * 1930-05-24 1939-08-15 William N Krebs Multifrequency signaling apparatus
GB464254A (en) * 1936-09-24 1937-04-14 Haardt & Co Ag Improvements in variable electrical condensers
US2223061A (en) * 1936-12-19 1940-11-26 Ducati Adriano Cavalieri Arrangement of noninductive terminals for variable condensers
US2295173A (en) * 1940-06-20 1942-09-08 Sonora Radio & Television Corp Step-wise tuning of electrical circuits
US2443935A (en) * 1942-01-07 1948-06-22 Gen Electric Superheterodyne radio receiver
US2344689A (en) * 1942-03-12 1944-03-21 Bendix Aviat Corp Variable capacitor
GB591258A (en) * 1944-05-12 1947-08-12 Patelhold Patentverwertung Improvements in or relating to short-wave tuning systems
US2557969A (en) * 1948-12-29 1951-06-26 Frank C Isely Shielded ultra high frequency tuning apparatus

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2886700A (en) * 1953-02-04 1959-05-12 Standard Coil Prod Co Inc Uhf-vhf tuners
US2913644A (en) * 1956-07-09 1959-11-17 Rca Corp Variable capacitor
US3056075A (en) * 1957-11-07 1962-09-25 Brayhead Ascot Ltd Turret tuners

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